ILLUSTRATIONS IX 



50. Brachiopoda {Lingnlella and Micktvitda) 318 



51. " (Mickzvitcia) 320 



52. " (Mickzvitsia and Oholella) 322- 



53. Trilobita {Callavia and Wanneria) 324 



54. " (Holmia and Olenellus) 326 



55. Fig. I. Robson Peak District. (Panoramic view from Shio 



Point, looking down Moose River Valley) 334-335 



Fig. 2. Robson Peak District. (Panoramic view of Tab 

 Peak, Mahto Momitain, and Calumet Creek) 334-335 



56. Fig. I. Robson Peak District. (Looking south across Calu- 



met Creek and Flats) 336-337 



Fig. 2. Robson Peak District. (Looking southwest ^rom 

 south slope of Mahto Mountain) 336-337 



57. Fig. I. Robson Peak District. (View from south slope of 



Mahto Mountain) 33^-339 



Fig. 2. Robson Peak District. (View from southwest slope 

 of Titkana Peak, looking south) 338-339 



58. Fig. I. Robson Peak District. (Panoramic view of the 



Robson massif from the ridge south of Mumm 



Peak) 340-341 



Fig. 2. Robson Peak District. (Panoramic view of the 

 Robson massif and adjoining mountains) 340-341 



59. Figs. I and 2. Robson Peak District. (Panoramic view of 



Mural Glacier) 342-343 



60. Dikeloccphalus minnesotensis Owen 392 



61. Dikelocephalinas (Dikeloccphalus and Saukia) 394 



62. " {Dikeloccphalus) 396 



63. " (Dikeloccphalus) 398 



64. " (Dikelocephalus, Saukia, Calvinella, and 

 Conokephalina) 400 



65. Dikelocephalinse (Saukia and Dikeloccphalus) 402 



66. " (Dikelocephalus and Saukia) 404 



67. " (Saukia) 406 



68. " (Conokephalina, Osceolia, and Calvinella). 40^ 



69. " (Saukia) 410 



70. " (Calvinella and Saukia) 412 



TEXT FIGURES 



Fig. I. Theoretical profile of North American continent 10 



2. Diagrammatic reconstruction of imagined primitive 



Pelmatozoic ancestor 43 



